Your proposal and your neighbour’s solar panels

In October 2018, Ministerial Planning Scheme Amendment VC149 introduced additional considerations for planning permit applicants into the Commercial 1 and Residential zones. The changes require specific consideration of a proposal’s impact on neighbouring rooftop solar energy generation facilities.

The new Decision Guidelines in the General Residential, Neighbourhood Residential, Township and Commercial 1 Zones include consideration of:

  • The impact of overshadowing on existing rooftop solar energy facilities on dwellings on adjoining lots in a General Residential Zone, Mixed Use Zone, Neighbourhood Residential Zone, Residential Growth Zone or Township Zone.

And for the Mixed Use and Residential Growth zones:

  • The impact of overshadowing on existing rooftop solar energy facilities on dwellings on adjoining lots in a Mixed Use Zone or Residential Growth Zone.

Amendment VC149 also changed Clauses 54 and 55 (ResCode) by including additional assessment Standards and Decision Guidelines relating to the impact on adjoining rooftop solar panels in a General Residential Zone, Neighbourhood Residential Zone or Township Zone.

It is noteworthy that the existing rooftop solar energy facility must exist at the date the planning application is lodged.

Since the introduction of these provisions the Victorian Civil and Administrative Tribunal has made a number of decisions that are relevant to permit applicants who are trying understand how to assess overshadowing of solar panels.

With the introduction of VC149, Practice Note 88: Planning Considerations for existing residential rooftop solar energy facilities was also released and provides guidance on the application of the new provisions. The Practice Note includes relevant factors to consider when determining whether any overshadowing is unreasonable, including:

  • The extent of existing overshadowing by existing structures.
  • Whether the new development meets the side and rear setback and north-facing windows standards for residential development under clauses 54 and 55.
  • Whether the protection of the existing rooftop solar energy facility will unreasonably constrain or compromise the proposed new development.
  • The type of existing rooftop solar energy facility. A multiple string system is less affected by shading than a single string system which is more vulnerable to shading, or any other system features such as micro inverters or bypass diodes which can operate with partial shading.
  • Whether the siting of the existing facility takes into account the potential future development of adjoining lots.
  • The extent to which the existing facility has been located to protect it from overshadowing through placement higher on the roof and further from existing lot boundaries to:
  • increase the separation between the panels and any neighbouring development and
  • reduce the height that any neighbouring development extends above the panels, minimising the likelihood of overshadowing

The following decisions illustrate how VCAT has interpreted these new provisions thus far and highlight some important considerations for permit applicants.

Mellas v Hobsons Bay CC [2019] VCAT 400 involved the construction of three double storey dwellings in the General Residential Zone. A neighbour appealed Council’s decision, raising concerns about overshadowing to solar panels (among other matters).

The Tribunal found that the extent of shadowing to neighbours’ solar panels was reasonable because:

  • A lower row of the neighbours’ panels on a single storey dwelling in an area where the Planning Scheme permits development up to 11 metres in height (General Residential Zone) was not ideally located to provide protection from shadow.
  • The complete avoidance of new shadow to the existing solar panels at the objector’s land would unreasonably constrain the development of the application site.

Cameron v Port Phillip CC [2019] VCAT 298 involved the construction of a dwelling in the General Residential Zone. The neighbour had an 8 panel solar facility adjoining the subject site. The Tribunal made an interim order and required further information, including:

  • When the energy facility was erected on the subject building.
  • The model and type of energy facility (including whether the facility is ‘multiple string’ or ‘single string’, or if the facility uses a ‘feed-in’ or ‘battery storage’ installation).
  • Any other system features of the energy facility, such as micro inverters or bypass diodes, that assist operations of the facility in partial shading.
  • The maximum power generated from the energy facility and details of typical solar power generated during a 24-hour day – over a 12-month period.
  • The estimated loss of energy efficiency from the facility that may arise from overshadowing of the panels from the proposed development on the review site.

In this instance the neighbour’s solar system was an older ‘single string’ system. It was submitted that, in these systems,  shading of any one of the panels would ‘significantly’ diminish energy output from the system. In its decision the Tribunal found that:

… the availability of an alternative location for the solar energy facility on the applicant’s property, including the age and use of single string panel technology, are all relevant considerations…


…an alternative location exists on the applicant’s site … [to] ensure unfettered access to sunlight throughout the day.

The Tribunal considered that the facility was outdated and suggested the applicant relocate the solar facility or upgrade the system.

Hall v Moreland CC [2018] VCAT 2022 involved the construction of a dwelling in the Neighbourhood Residential Zone. The neighbour was concerned about the impact on his solar (single stream) system during the warm months of the year, generally after 4.30 pm until approximately 7.30 pm in the summer months.

The Tribunal noted that the zone provided for a dwelling height up to 9 metres and two storeys and that the construction of a single stream solar system was unsatisfactory in those circumstances, and also that overshadowing of the system could occur from other circumstances such as vegetation growth or other structures not requiring a planning permit. It was indicated that while it may be unfeasible to modify the system, that issue needs to be balanced against whether it is unreasonable to constrain or compromise a modest redevelopment on an adjoining lot.

Beal v Yarra CC [2019] VCAT 411 involved the construction of a two storey extension to a dwelling in the Neighbourhood Residential zone. The dwelling to the south of the proposal had a bank of 12 solar panels on the north facing roof plane.  In the appeal made by neighbours, the Tribunal was not able to properly assess the impacts on the appellant’s solar system as the appellant had not provided details of the age, quality and type of system, it’s maximum capacity and extent of loss of energy efficiency. The Tribunal found that the appellant’s panels had not been installed in an optimal location.

In a recent request for further information Clause 1 was asked to provide the following:

  • 3D shadow or sectional shadow drawings to show the extent of shadow cast over the existing solar panels on the adjoining property. Shadow drawings must include the following times (daylight hours which provide function to solar panels):
    • winter solstice 22 June between 8am and 5pm
    • equinox 22 September between 7am and 5pm
    • summer solstice 22 December between 7am to 7pm
  • If solar panels are overshadowed, details (if possible) of the type of the existing rooftop solar energy facility e.g. single string or multiple string / or any other system features such as micro inverters or bypass diodes which can operate with partial shading.
  • An outline of how overshadowing of any existing rooftop solar energy facility is proposed to be mitigated.

Our recommendation to planning permit applicants is to ensure the location of neighbours’ solar systems are included in the initial site feature survey and shown on plans. Where there is potential for the overshadowing of those panels, sectional shadow diagrams should be provided (throughout the times listed above) along with a written submission assessing the location of panels and other criteria listed in the new Decision Guidelines and recent VCAT decisions.

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